胎儿后颅窝超声检查：枕大池蛛网膜囊肿和Dandy-Walker变异的假像

Sonography of the fetal posterior fossa: false appearance of mega-cisterna magna and Dandy-Walker variant.

作者信息

Laing F C, Frates M C, Brown D L, Benson C B, Di Salvo D N, Doubilet P M

机构信息

Department of Radiology, Brigham and Women's Hospital, Boston, MA 02115.

出版信息

Radiology. 1994 Jul;192(1):247-51. doi: 10.1148/radiology.192.1.8208946.

DOI:10.1148/radiology.192.1.8208946

PMID:8208946

Abstract

PURPOSE

To establish that incorrect scanning of the fetal posterior fossa may falsely create the appearance of a mega-cisterna magna (MCM) or Dandy-Walker variant (DWV).

MATERIALS AND METHODS

After routine sonography, 100 consecutive fetuses (gestational age range, 25-40 weeks) without abnormality underwent additional posterior fossa scanning in an attempt to create the appearance of an MCM (anteroposterior diameter larger than 10 mm) or DWV. Sonograms were obtained in a plane inferior to or angled more coronally than the routine axial plane.

RESULTS

The posterior fossa was depicted in 93 fetuses. Pseudo-MCM occurred in 35 (38%) of 93 fetuses: 12 (30%) of 40 fetuses aged 25.0-29.9 weeks, 11 (50%) of 22 fetuses aged 30.0-34.9 weeks, and 12 (39%) of 31 fetuses aged 35.0-40.0 weeks. Pseudo-DWV occurred in 40 (43%) of 93 fetuses: 20 (50%) of 40 fetuses aged 25.0-29.9 weeks, 12 (55%) of 22 fetuses aged 30.0-34.9 weeks, and eight (26%) of 31 fetuses aged 35.0-40.0 weeks.

CONCLUSION

Sonography of the posterior fossa in an angled semi-coronal plane should be avoided because it may create an appearance that mimics an abnormality.

摘要

目的

证实胎儿后颅窝扫描不正确可能会错误地造成巨大枕大池（MCM）或Dandy-Walker变异型（DWV）的假象。

材料与方法

在常规超声检查后，对100例无异常的连续胎儿（孕周范围为25 - 40周）进行额外的后颅窝扫描，试图制造出MCM（前后径大于10 mm）或DWV的假象。在低于常规轴位平面或角度更偏向冠状面的平面获取超声图像。

结果

93例胎儿的后颅窝被显示出来。93例胎儿中有35例（38%）出现假性MCM：25.0 - 29.9周龄的40例胎儿中有12例（30%），30.0 - 34.9周龄的22例胎儿中有11例（50%），35.0 - 40.0周龄的31例胎儿中有12例（39%）。93例胎儿中有40例（43%）出现假性DWV：25.0 - 29.9周龄的40例胎儿中有20例（50%），30.0 - 34.9周龄的22例胎儿中有12例（55%），35.0 - 40.0周龄的31例胎儿中有8例（26%）。